The present invention relates to a semiconductor device and a method for manufacturing a semiconductor device.
In recent years, various structures of semiconductor devices have been proposed with a trend for miniaturization of wirings in semiconductor devices.
Patent Document 1 (Japanese Unexamined Patent Publication No. 11-121612) describes the following method for manufacturing a semiconductor device. First, a trench is formed in an interlayer insulation film over a semiconductor substrate. Then, a metal is filled in the inside of the trench. Then, a part of the metal is etched in a prescribed amount. As a result, a lower-layer wiring and a columnar coupling part are formed of the same metal as an integral structure at the same time. This can provide a high-reliability wiring structure.